c0pperdragon

Yes, U5E should not be all too important for the clock signals shape.

Yes, inserting/removing an inverter there makes no difference. I actually no not consider the signal from the crystal of being any specific phase until it is used for some useful...

Looks OK to me. With this setup you can use a RAM IC with up to 1MB, as you said. What kind of parts to you intend to use? As...

Maybe it is a little late now, but I actually found the perfect solution to add auxilary ICs to the OS816 architecture without modifying the original memory map, so there...

Yes, that is right. You get 3 RW#/WR# ranges (4 MB each) and 8 ranges for the CS# pins. (512KB each). And the 4th R/W pair generates the access signals...

I don't think you need to change anything with the timings and run with 16MHz just fine. The timings are normally adjusted by the Arduino libraries accordingly. 8 MHz was...

Brobably, but for this kind of bus-sniffing, the current code is a real overkill. Maybe you want to do you own research on how to program such a thing from...

very nice. and sure, use the code wherever you like

I did not make special requirements in this regard to make the software work with any arduino compatible device. When I designed my board, I could not get an Atmega328P,...

The scope traces already show both the even and the odd frame and also the two adjacent hsync pulses (together with the color burst). Before and after everything is completely...